1. Field of the Invention
The present invention relates to a dynamo-electric machine which comprises equalizing connectors electrically connecting commutator segments which should have the same electric potential to each other, and to a method of manufacture therefor.
2. Description of the Related Art
FIG. 14 is a partial cross-section of an electric motor which is a conventional dynamo-electric machine. In this electric motor, a commutator assembly 101 is disposed in the vicinity of an armature 100.
The armature 100 comprises: a core 102 having slots extending in the axial direction; and a winding 103 composed of wiring wound by a lap winding method through the slots.
The commutator assembly comprises: a commutator 105 having commutator segments 104 arranged around its circumference and risers 106 electrically connected to the winding 103; brushes (not shown) which contact the commutator segments 104; and equalizing connectors 107 electrically connecting commutator segments 104 which should have the same electric potential to each other. End portions 108 of the equalizing connectors 107 shown in FIG. 15 are secured to the risers 106 by brazing, etc. The equalizing connectors 107 are secured and supported by a securing member 109, enabling the equalizing connectors 107 to withstand centrifugal force.
In the above 4-pole lap-wound electric motor, an electric current is supplied to the winding 103 from outside by means of the brushes contacting the commutator segments 104, whereby the armature 100, equalizing connectors 107, and the commutator 105, which are all secured to a rotating shaft (not shown), rotate together with the shaft due to electromagnetic effects.
In an electric motor of the above construction, the equalizing connectors 107 are provided to prevent circulating currents which run through the brushes generated by differences in induced voltage between circuits in the winding 103, but one problem is that these equalizing connectors 107 require the securing members 109 for support, increasing the number of parts.
Another problem is that space is required to hold the equalizing connectors 107 and the securing members 109, and such space is difficult to procure, particularly in a small electric motor for use in an automobile.